Los yesos del Mioceno superior de Campo Coy (Cordillera Bética oriental, España)

The Campo Coy basin contains an important evaporite succession, up to 350 meters thick of gypsum, including two gypsum units: lower and upper gypsum units. These are characterized by fine-grain laminated and selenitic primary gypsums and by nodular-laminated and meganodular secondary gypsums. The geochemical study based on sulfate isotope compositions (δ34S and δ18O) and strontium isotope ratios (87Sr/86Sr) point to the chemical recycling of Triassic marine evaporites. Isotope compositions (δ18O and δD) of the hydration water of gypsum point to continental waters for primary gypsum precipitation. These results are consistent with a shallow lacustrine environment for the Campo Coy gypsum deposit.La cuenca de Campo Coy registra una sucesión evaporítica de más de 350 metros de potencia de yeso, dividida en dos unidades de yesos: unidad inferior y unidad superior. Estas unidades están formadas por litofacies de yeso primario laminado y yeso selenítico junto con litofacies de yeso secundario laminado-nodular y meganodular. El estudio geoquímico de la composición isotópica del sulfato (δ34S y δ18O) y de la relación isotópica del estroncio (87Sr/86Sr) muestra valores indicativos del reciclaje de evaporitas marinas triásicas. Los valores isotópicos del agua de hidratación del yeso (δ18O y δD) indican aguas de origen continental para el yeso primario. Estos resultados reflejan un ambiente lacustre somero durante la formación del depósito evaporítico de Campo Coy.This study was supported by the projects CGL-2013-42689 and CGL2016-79458 of the Spanish Government

Sulfate isotope composition of Messinian evaporites in the Piedmont basin (Italy)

The Piedmont basin (NW Italy) records a Messinian Salinity Crisis (MSC) succession including a selenite gypsum deposit assigned to the Primary Lower Gypsum (PLG, MSC stage 1). Strontium isotope ratios are in the range of the PLG deposits of the Mediterranean area. Sulfate isotope compositions of vertically oriented selenite gypsum beds, in the lower part of the succession, are similar to those reported in other PLG deposits. However, flattened branching selenite cones in the upper part show higher isotope compositions, mainly in δ34S values, suggesting intense BSR conditions, stronger than reported in other PLG deposits. We interpret this chemical shift during deposition of the upper part of the PLG as the result of increased marine restriction assisted by the marginal position of this basin in the Adriatic Gulf during the Apennine and Alpine uplifts

Further insights in trichothiodistrophy: a clinical, microscopic, and ultrastructural study of 20 cases and literature review

Background: Trichothiodistrophy (TTD) is a rare autosomal recessive condition that is characterized by a specific congenital hair shaft dysplasia caused by deficiency of sulfur associated with a wide spectrum of multisystem abnormalities. In this article, we study clinical, microscopic, and ultrastructural findings of 20 patients with TTD with the aim to add further insights regarding to this rare condition. Additionally, analyses of our results are compared with those extracted from the literature in order to enhance its comprehensibility. Materials and Methods: Twenty cases of TTD were included: 7 from Mexico and 14 from Spain. Clinical, microscopic, scanning electron microscopy (SEM) studies and X-ray microanalysis (XrMa) were carried out in all of them. Genetic studies were performed in all seven Mexican cases. Patients with xeroderma pigmentosum and xeroderma pigmentosum/TTD-complex were excluded. Results: Cuticular changes and longitudinal crests of the hair shaft were demonstrated. These crests were irregular, disorganized, following the hair longest axis. Hair shaft sulfur deficiency was disposed discontinuously and intermittently rather than uniformly. This severe decrease of sulfur contents was located close to the trichoschisis areas. Only five patients did not show related disturbances. Micro-dolichocephaly was observed in five cases and represented the most frequent facial dysmorphism found. It is also remarkable that all patients with urologic malformations also combined diverse neurologic disorders. Moreover, three Mexican sisters demonstrated the coexistence of scarce pubic vellus hair, developmental delay, onychodystrophy, and maxillar/mandibullar hypoplasia. Conclusions: TTD phenotype has greatly varied from very subtle forms to severe alterations such as neurologic abnormalities, blindness, lamellar ichthyosis and gonadal malformations. Herein, a multisystem study should be performed mandatorily in patients diagnosed with TTD

Further insights in trichothiodistrophy: A clinical, microscopic, and ultrastructural study of 20 cases and literature review

Trichothiodistrophy (TTD) is a rare autosomal recessive condition that is characterized by a specific congenital hair shaft dysplasia caused by deficiency of sulfur associated with a wide spectrum of multisystem abnormalities. In this article, we study clinical, microscopic, and ultrastructural findings of 20 patients with TTD with the aim to add further insights regarding to this rare condition. Additionally, analyses of our results are compared with those extracted from the literature in order to enhance its comprehensibility. Materials and Methods: Twenty cases of TTD were included: 7 from Mexico and 14 from Spain. Clinical, microscopic, scanning electron microscopy (SEM) studies and X-ray microanalysis (XrMa) were carried out in all of them. Genetic studies were performed in all seven Mexican cases. Patients with xeroderma pigmentosum and xeroderma pigmentosum/TTD-complex were excluded. Results: Cuticular changes and longitudinal crests of the hair shaft were demonstrated. These crests were irregular, disorganized, following the hair longest axis. Hair shaft sulfur deficiency was disposed discontinuously and intermittently rather than uniformly. This severe decrease of sulfur contents was located close to the trichoschisis areas. Only five patients did not show related disturbances. Micro-dolichocephaly was observed in five cases and represented the most frequent facial dysmorphism found. It is also remarkable that all patients with urologic malformations also combined diverse neurologic disorders. Moreover, three Mexican sisters demonstrated the coexistence of scarce pubic vellus hair, developmental delay, onychodystrophy, and maxillar/mandibullar hypoplasia. Conclusions: TTD phenotype has greatly varied from very subtle forms to severe alterations such as neurologic abnormalities, blindness, lamellar ichthyosis and gonadal malformations. Herein, a multisystem study should be performed mandatorily in patients diagnosed with TTD

Advanced applications of scanning electron microscopy in geology

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32166Nowadays Scanning Electron Microscopy (SEM) is a basic and fundamental tool in the study of geologic samples. The collision of a highlyaccelerated electron beam with the atoms of a solid sample results in the production of several radiation types than can be detected and analysed by specific detectors, providing information of the chemistry and crystallography of the studied material. From this point of view, the chamber of a SEM can be considered as a laboratory where different experiments can be carried out. The application of SEM to geology, especially in the fields of mineralogy and petrology has been summarised by Reed (1996).The aim of this paper is to show some recent applications in the characterization of geologic materials

Occurrence of a new sulphate mineral: Ca7Na3K(SO4)9 in the Emet borate deposits, western Anatolia (Turkey)

This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal size hinders the appropriate chemical and crystallographic characterization required to propose it as a new mineral to the International Mineralogical Association.

Large gypsum nodules in the Paleogene and Neogene evaporites of Spain: distribution and palaeogeographic significance

Sabkha and deep burial set tings are the most com mon sites where diagenetic anhydrite forms. In a sabkha setting, displacive facies (iso lated nodules, bed ded nodules, enterolithic levels) of early diagenetic or primary anhydrite are generated (Shearman, 1966; Hardie, 1967). These anhydrite facies are commonly foundat the top of shoal ing cycles representing the evolution from subaqueous depositional conditions at the base (carbonates, lutites) to exposure conditions at the top where in ter stitially-grown gypsum/anhydrite de velops ( sabkha cy cles). In a deep burial setting, gypsum transforms to tally to anhydrite with in creas ing temperature and lithostatic pressure (Murray, 1964). Al though this mineral transformation usually preserves the depositional gypsum facies, a significant textural change is in volved in other cases, resulting in replacive anhydrite with a nodular-mosaic or"chicken-wire" fabric (Warren, 2006). In the two settings, how ever, the size of the individual anhydrite nodules is relatively small, rarely reaching some tens of centimetres across. More over, bedding is preserved or little disturbed, al though minor de formation is caused by the displacive sabkha nodules

Comportamiento geoquimico de las formaciones salinas bajo el efecto de la temperatura y la irradiacion

La generación de defectos cristalinos y la migración de las fases fluidas (salmueras y gases), son los efectos más relevantes de la irradiación y la temperatura sobre una formación salina, susceptible de albergar un almacenamiento de residuos radiactivos. Para determinar dichos efectos se ha puesto a punto la metodología necesaria y se ha verificado sobre muestras salinas de la mina de Sallent (Barcelona). El contenido en agua oscila entre 0,04 y 1 %. Sin embargo, la cantidad de salmuera susceptible de migrar será inferior a la total, debido a que parte de esta se encuentra en inclusiones fluidas inferiores a 100 mm. La composición química de la salmuera, factor clave para el estudio de corrosión de contenedores, es de carácter magnésico (1,15 moles/litro) y potásico (0,31 moles/litro) en el caso de las inclusiones. El análisis de los gases presentes indica la ausencia de gases tóxicos y concentraciones muy bajas de hidrógeno y metano. Finalmente, se ha observado que la generación de defectos por irradiación, está en relación directa con la presencia de impurezas en la roca, siendo concordantes los resultados experimentales con las predicciones del modelo de JainLidiard